S&S CYCLE 106" Big Bore Forged Pistons For '07-'16 HD® Big Twins - 3.927" Standard Bore - 106-3690

These big bore pistons work with the stock 4-3/8" stroke flywheels to convert any 2007-'16 HD^® big twin engine from 96" or 103" to 106" displacement with 10:1 compression with stock heads. Stock cylinders may be bored to accomodate larger pistons, but we recommend S&S 3.927" bore cylinders which feature high strength alloyed cast iron liners. Pistons are compatible with stock rods with tapered wristpin ends. S&S^® 3.927" bore pistons are machined to such close tolerances that it is not necessary to measure the piston. Just bore cylinders to nominal diameter +/- 0.0005" for correct clearance. Additionally, the low friction coating on the piston skirt makes taking measurements very difficult. 3.927" standard bore.

• Piston kit includes forged pistons (unless noted) rings, wrist pins and clips for a complete motor replacement
• Made in the U.S.A
  
  NOTES: S&S 3.927" pistons are machined to such close tolerances that it is not necessary to measure the piston. Additionally, the low friction coating on the piston skirt of early production pistons with out micrometer window makes taking measurements very difficult. Therefore, hone cylinders to nominal diameter +/- 0.0001" for correct clearance. Current production pistons have micrometer windows in the coating on the piston skirts that allow accurate measurements to be taken. These pistons may be installed by honing cylinder to nominal diameter +/- 0.0001" or by measuring piston and honing cylinder to achieve .002" - .0025" close clearance for street applications or .0032" - .0045" loose clearance for immediate competition use.

Fitment Guide

Specs